A spur toothing of said type is provided, for example according to DE 36 36 243 A1, in a wheel bearing unit. In the wheel bearing unit, a hub is rotatably mounted by means of a wheel bearing. The hub is connected rotationally fixed connected to a vehicle wheel and can be driven by a cardan shaft arrangement. In the case considered, the hub is coupled to the cardan shaft arrangement. Provided as a coupling element is the bell of a joint, on which bell the spur toothing is formed. The spur toothing faces axially toward a corresponding mating toothing. The mating toothing is likewise a spur toothing and is formed directly on the hub or on an inner ring, which is seated on the hub, of the wheel bearing. The spur toothings engage into one another axially and are clamped to one another axially. By means of said connection, torques about the rotational axis from the cardan shaft arrangement to the hub and therefore to the vehicle wheel, or in the inverse direction are transmittable. The toothings are generally clamped to one another axially in such a way that the tooth flanks are uniformly loaded. This assumes, however, that the geometry of the toothing is formed very precisely, so that the load-bearing component which acts axially and at the peripheral side is very high.
It is provided according to DE 36 36 243 A1 that the spur toothings are formed by cold-forming of certain regions of the material of the coupling elements. For this purpose, the material is plastically displaced by feeding forming dies from the axial direction and partially also by pivoting the dies relative to the rotational axis in the radial direction. The resistance of the material against displacement is particularly high, especially at the coupling element of the cardan shaft arrangement, since the material must be formed directly out of the surface of the coupling element and therefore out of a relatively large and solid material accumulation. The forces required for the forming process are very high. Machines having the correspondingly high required power are expensive. It is difficult to form individual teeth of the toothing with the required accuracy and with a high load-bearing component of the teeth, since a large part of the material escapes radially outward on account of the high forming forces, and does not flow into the forming die.